This invention relates broadly to pressure-responsive valves for fluid dispensing containers, and is more particularly directed to a pressure-responsive valve which can also be used as a closure as well as a method for making it.
Many fluid materials, especially liquids and pastes, especially useful in the fields of personal hygiene, cosmetics and toiletries employ materials that deteriorate during a long storage. Thus, for example, many perfumes, colognes, aftershaves and the like contain alcohol as an important constituent. The evaporation of the alcohol over a long period of time deteriorates the the material. Almost everyone has experienced trying to remove toothpaste from a tube that has been left open. Often times one encounters a slight block of dried out toothpaste which prevents further use of the tube without gouging the dried material out of the neck. Similar problems arise out of the storage of lotions, creams and the like. Likewise, a variety of industrial material which employs volatile solvents may encounter similar problems.
To reduce or eliminate such problems, the present invention proposes the inclusion of a self-closing valve mechanism which is automatically opened when the contents of a container are to be dispensed and automatically closes itself upon the discontinuance of the dispensing operation, whereby to prevent deterioration due to oxidation, evaporation or other deteriorating aging phenomenon. Particularly the valve mechanism contemplated in this application is a pressure responsive valve which is self-restoring to a closed position upon removal of the actuating pressure.
The pressure-responsive valve of the present invention employs a novel slit arrangement in an elastically deformable membrane. This slit arrangement permits the valve to open upon the application of pressure to one side of the diaphragm and provides sufficient restorative force to cause the valve to close when the pressure is discontinued.
This valve may be employed in gas dispensing but it presently finds its major utility in liquid dispensing containers where pressure is transmitted to the valve either by an applicator in the mouth of the container or by squeezing the container to cause the pressurized liquid to impinge against the diaphragm and open the slits. The first arrangement is particularly suited to dabbing type applicators where the container is provided with an applicator pad which is pressed against the surface to be dabbed. The pressure applied to the applicator is transmitted to the valve causing it to open whereby fluid is permitted to flow from the container to the applicator.
Another aspect of the present invention is that the valve may be supplied in the form of a closure which is capable of being converted into a pressure-responsive valve. This is accomplished by partially cutting the slits so that they do not completely penetrate the diaphragm. The diaphragm may thus be used as a positive seal. When pressure is applied, the slits open up breaking the seal and the diaphragm is converted into a pressure-responsive valve.
Conventional pressure-responsive valves have a drawback because they are incapable of exerting sufficient restorative force to close themselves tightly after a number of open and close cycles have been completed. In a sense, they wear out. This is because they rely on simple flap action wherein the restorative force is exerted by a line of material. Examples may be found in U.S. Pat. Nos. 3,418,055 and 3,669,323.
The principal object of this invention is to provide a pressure-responsive one-way valve which opens upon the application of pressure yet exerts sufficient restorative force to return to a normally closed position upon the cessation of the application of pressure.
Another object of this invention is to provide a closure for a container affording a positive seal to protect against evaporation which can be broken upon the application of pressure and thereby converted into a pressure-responsive valve.
Another object of this invention is to provide a liquid dispensing device employing the valve of the present invention.
Another object of this invention is to provide a means for concentrating the restorative force of an applicator pad so as to add the restorative force of the pad to the restorative force of the valve.
A further object of this invention is to provide a method for cutting slits in a planar diaphragm at an angle to the plane of the diaphragm, other than at a right angle.